An Angel In Beacon Hills
by ThornyRose463
Summary: Supernatural and Teen Wolf crossover story featuring a female Castiel. Cassandra (played by Skyler Samuels) is the youngest of the angels. She moves to Beacon Hills with Dean and Sam Winchester and starts having a relationship with Derek Hale. Disclaimer: I don't own Supernatural or Teen Wolf.
1. Chapter 1

Chapter 1

Cassandra didn't know why, but she had a feeling that she must be in Beacon Hills. Dean Winchester and his brother Sam came with her when she moved to the town.

After Dean drove his black 1967 Chevrolet Impala to their new apartment, they settled in and then walked around the town, checking it out.

After half an hour, Dean's stomach rumbled.

"Looks like it's lunch time." Dean rubbed his stomach.

"You go get food," Cassandra said. "I'm going to walk around a bit more."

"Okay. We'll meet you back at the apartment," Sam said.

Cassandra nodded and waved Dean and Sam goodbye.

* * *

Cassandra kept walking until she came across a broken down Jeep with its hood up. She walked over to the boy trying to fix it. He was mumbling to himself as he meddled around with a wrench.

"Do you need help?" Cassandra asked him as she got closer.

He was startled for a moment but then turned to face Cassandra. "No...Uh...I got it. It does this all the time. I'm kind of used to it."

He continued tinkering. Cassandra didn't say anything. She just stood there and watched him.

"There!" He shouted. He walked around and got into his car. He tried turning it on, and he received a tease of his success from the engine until it died down again. He got out of his car and was about to try fixing it, when he saw Cassandra still standing there.

"May I?" She asked, holding out her hand.

He sighed and handed her the wrench. "Fine."

Cassandra took a few steps closer and pretended to tinker a bit.

"Try it now," Cassandra said.

He gave Cassandra a doubtful look before he went back to his car. Cassandra took this opportunity to fix the car with her powers. He turned the car on, and the engine sounded even better than it did when he first got the car. He jumped out of the car, shocked. "How did you do that?"

"I-" Cassandra didn't know what to say.

"Stiles, you got the car started. Let's go." Derek said. He had been in the car the whole time.

Cassandra looked at Derek. He looked to be in his 20's — like her vessel.

Cassandra's vessel had fair skin, straight brown hair that reached her mid-back, blue eyes, thin eyebrows, and a slim build and wore a black t-shirt underneath an unzipped black leather jacket, and a pair of dark blue denim jeans tucked into knee-length black leather boots without buckles or zippers.

"I have to go home. Goodbye." Cassandra turned around and walked away.

"Who the hell was that?" Derek questioned.

"No idea." Stiles responded. "But she fixed my car. Now let's go. Scott is still waiting for us."

"She smells different," Derek muttered.

"Smells? Like a good smell or like a bad smelly smell?" Stiles asked.

"She smells intoxicating and alluring," Derek said. "I'm not sure if that's a good thing or a bad thing."

* * *

It had been six months since Cassandra moved to Beacon Hills with Dean and Sam, five months since she met Derek Hale, and three months since she started having a relationship with Derek.

She remembered when she first saw Derek, which was when she arrived in Beacon Hills, but she didn't talk to him, nor did she find out his name. It was just a passing glance. He was inside Stiles' Jeep, waiting for Stiles to fix the smoking car. She had secretly used her powers to fix Stiles' Jeep.

She ran into Derek five more times in that month before he decided to talk to her. He told her that he talked to her because her smell was intoxicating and alluring.

Cassandra was sitting next to Derek on the couch in his apartment. Today was the day she was going to tell him that she was an angel.

Unbeknownst to Cassandra, Derek also had something to confess.

Cassandra turned to face Derek. They both opened their mouths to talk, but neither of them said anything.

"Go ahead," Derek said.

"Derek...there's something I haven't told you about myself." Cassandra said. "I am an angel."

Derek was shocked. "An angel? An actual angel?"

"Yes. Forgive me for not saying so earlier," Cassandra said.

"I have a secret of my own." Derek paused. "I'm a werewolf."

Cassandra was shocked. "A-A werewolf?"

"Yeah, but an angel? That's a lot more impressive," Derek said.

"No...I'm actually the youngest of the angels. The others are much stronger than I am." Cassandra waved him off. She and Derek laughed.

"Remember the friends I told you about? All of them are something supernatural. Except Stiles. He's human," Derek said. "Would you like me to take you to meet them?"

"I would like that very much," Cassandra said.

Derek smiled, taking Cassandra's hand as he stood.

* * *

"This is Scott. He's also a werewolf. You already know Stiles." Derek started introducing everyone.

"Hi. Stiles. Human." Stiles greeted.

Cassandra chuckled.

"Malia is a werecoyote. Lydia is a banshee. Kira is a kitsune." Derek continued. "Everyone, this is my girlfriend, Cassandra."

"You smell different," Malia muttered as she smelled Cassandra. "What are you?"

"I am an angel." Cassandra said.

"What? Really?!" Stiles shouted. "An angel? An actual angel? Like halo and wings?"

"That is correct...though my wings cannot be seen by anyone who is not an angel." Cassandra looked down in shame. "My wings are a bit broken, so they aren't a worthy sight to see."

Derek took Cassandra's hand and gave it a reassuring squeeze. She turned towards him. He smiled.

"How many angels are there?" Kira asked Cassandra.

"There are more angels than there are humans," Cassandra said.

Cassandra talked with the teenagers for hours, then she got a call from Dean on her cell phone. "You're leaving? I see. Shall I go with you? Are you sure? I will go right away."

Cassandra hung up her phone.

"Should I take you home?" Derek asked Cassandra.

"I'll show you some of my powers first," Cassandra said. "My wings might be a bit broken, but I can still fly."

Cassandra put a hand on Derek's shoulder. In a second, they were in front of her, Dean, and Sam's apartment, leaving the teenagers in awe of what she was able to do.

Dean and Sam came out of the apartment with their duffel bags

Dean smiled at Cassandra. His smile faded when he saw Derek. He and Sam still hadn't met Derek.

"Dean, Sam, I have returned." Cassandra said.

"Is this…uh...is this the guy you've been telling us about?" Sam asked.

Cassandra nodded. "Yes, this is Derek."

"You're Sam, right?" Derek held a hand out for Sam to shake.

"That means you're Dean," Derek added after he shook Sam's hand.

Dean took his duffel bag and walked over to his car. "Yeah, I'm Dean."

"Are you sure you don't need me on your next hunt?" Cassandra asked.

"I think you're needed more here than you're needed with us," Sam said.

"They're just a bunch of vamps." Dean came back and stood in front of Derek, as if to size him up. "Sam, get the rest of the stuff."

"I'll help you, Sam." Cassandra followed Sam into the apartment.

"Cassandra is like the sister Sam and I never had. If anything bad happens to her, I will kick your ass. Do you understand me?" Dean growled, stepping into Derek's space.

"I'll take care of her, I promise." Derek responded.

Dean nodded, satisfied with Derek's response. "Good."

Cassandra and Sam came out with the remaining things.

"Let's get going," Dean called out to Sam.

Dean and Sam got into Dean's car and left.

Cassandra waved the Winchester brothers goodbye until they were out of sight. Once they were, Derek gave her a peck on the lips.

"I love you," Derek said.

Cassandra smiled. "I love you too, Derek."


	2. Chapter 2

Chapter 2

"Hello, Derek," Cassandra said happily as she entered Derek's apartment. She hadn't seen him over the past few weeks, since she was out hunting.

"You're back," Derek said, standing from his spot on the couch.

Derek smiled for what seemed like the first time over the past few weeks.

"I'm sorry I keep having to leave suddenly." Cassandra let her head hang slightly out of guilt.

Derek's smile faded. "Yeah...I get that you help Dean and Sam all the time, but to be honest, I kind of wish you were around a little more."

"Forgive me for causing you such grief. I don't mean to...but you know I have to help them out," Cassandra said.

Derek nodded. "I know. Trust me, I understand that, but..."

Cassandra heard Gabriel's voice through the angel radio. "Hey, Cassandra, can you pop over for a bit? I need your help with something."

"Cassandra, are you listening?" Derek asked before letting out a sigh. "They're calling for you again, aren't they?"

"It's not Dean, nor is it Sam. It's Gabriel. I know it's bad timing, but...can I?" Cassandra asked.

Derek sighed again and turned away from Cassandra. "Go."

Cassandra smiled sadly before turning to leave.

Derek turned around suddenly. "Wait, who is Gabr...?"

Cassandra was gone before Derek could say 'Gabriel'.

Derek slumped onto his couch.

* * *

"What is it that you need my help with, Gabriel?" Cassandra questioned.

"Well, someone woke up on the wrong side of Heaven. Catch you at a bad time or what?" Gabriel joked.

"I was...having an argument," Cassandra said.

"An argument? With Dean and Sam? That's a first," Gabriel said.

"No...Actually, it was with my...um...my boyfriend," Cassandra said.

"BOYFRIEND? Since when does my darling sister have a boyfriend? How come you haven't told me about him? What's his name?" Gabriel asked rapidly.

Cassandra looked away, suddenly feeling embarrassed. "His name is Derek. He is a werewolf, but he does not eat people. He has an amazing smile, and his eyes are as bright as his soul."

Gabriel smiled. "You really love him, huh?"

"What was the fight about? Need me to play a trick on him? Maybe two?" Gabriel asked playfully.

"I do love him...but it seems he is unhappy with the fact that I am away too often. Though I am also quite saddened that I haven't seen him as of late, I can't just stop helping the Winchesters." Cassandra said.

"And I caught you in the middle of that, eh? Sorry about that, sis," Gabriel said. "Let me give you a piece of advice. If you wanna spend time with Derek, then just tell Dean and Sam. I'm sure they'll understand. They got along just fine before you. They'll survive without you."

"You think so?" Cassandra questioned.

"You said you love him, right?" Gabriel asked. Cassandra nodded. "Then go spend time with him."

"But you-" Cassandra started.

"Don't worry about me. I was just gonna ask you to help set up this prank for Balthazar, but I don't really need you. I'm the trickster, remember?" Gabriel turned away and snapped his fingers, and Cassandra appeared back at Derek's apartment.

Derek was lying on his couch, an open book over his face as he slept.

Cassandra smiled and slowly removed the book to expose Derek's sleeping face. She reached out and caressed his cheek. "I love you," she whispered.

"I love you too," Derek responded drowsily, which startled Cassandra.

Derek sat up. "Didn't expect to see you here so soon."

"I...Yes, well...Gabriel let me come back." Cassandra looked away so that Derek wouldn't see her reddened cheeks.

"Yeah, about that...Who is Gabriel? Is he-" Derek started. Seeing Cassandra tilt her head, he stopped. "Never mind."

"What is it that you want to know about Gabriel?" Cassandra asked.

"Well, you usually always go out and help Dean and Sam. Gabriel was...a new name. Is he...Is he someone you...you like?" Derek asked.

Cassandra was confused. "Of course I like Gabriel. Why wouldn't I?"

"Do you love him? Do you leave on these 'hunts' to go see him?" Anger was apparent in Derek's voice.

"Yes, I love him, but I go on hunts to help the Winchester brothers. I don't often visit Gabriel. Why?" Cassandra asked.

Gabriel suddenly appeared behind Cassandra.

"What the hell?!" Derek shouted.

Gabriel smirked. "Someone call me?"

"You're Gabriel?" Derek asked.

"The one and only," Gabriel said.

"I should introduce you." Cassandra said. "Derek, this is my brother, Gabriel. Gabriel, this is my boyfriend, Derek."

"B-Brother? Gabriel is your brother? You didn't tell me you had a brother," Derek said while reaching out his hand to shake Gabriel's.

"All angels are my siblings," Cassandra said.

Gabriel brought Derek closer to him. "Yeah, and I'm part of the archangel section so...yeah, very powerful, in case you needed to know."

"R-right," Derek said.

"Gabriel, weren't you busy?" Cassandra asked.

"I was more curious about your boyfriend here, but I saw him. I'll leave now and give you two the space you need." Gabriel winked.

"GABRIEL!" Cassandra shouted.

Gabriel laughed and then left.

Derek took Cassandra's hand. "I'm sorry for getting angry earlier."

"No, no...The fault is mine." Cassandra said. "I promise I'll be around more. I don't like being away from you."

Derek leaned in and rested his forehead on Cassandra's. "I love you," he whispered.

"I love you too," Cassandra said.

Derek and Cassandra smiled at each other before Derek kissed Cassandra softly.


	3. Chapter 3

Chapter 3

"Wanna join us for a hunt?" Dean asked with a hint of enthusiasm, much to Cassandra's surprise.

After all, he had always been a bit apprehensive when it came to inviting people on hunts. Especially when, though they were great people, Scott's pack was part of the supernatural world.

Sure, it had been a little over a year since they met, but for Dean Winchester to offer them to join a hunt was more than a little surprising. Not that Cassandra was complaining, of course. She was worried that they would get hurt, but any little bit of time she could spend with Derek was great.

"You want us to help you?" Scott asked. He seemed a little hesitant as well. He hated fighting and only did it when he had to protect his family and friends.

Dean shrugged. "Well, yeah. You guys are strong, but you have to think long and hard about this. Hunting isn't for everyone."

"Why? What...What would we be hunting?" Stiles asked from his spot behind Scott. He looked a little nervous, but he tried to hide it. His mind was going a million miles a second.

Sam smiled sympathetically. "We're not one hundred percent sure yet, but from the looks of it, could be a demon or two. Worst case, a group, but it doesn't look like it's that bad."

"Like Dean said, you don't have to do this if you don't want to. I'd prefer it if you stayed here where it is safe," Cassandra said. She was holding Derek's hand, and she gave it a squeeze as she looked over at him. "I would hate it if any of you were injured."

"I'm game." Derek met Cassandra's gaze and smiled.

Cassandra returned his smile, only for it to break into a look of worry.

"Are you certain?" She asked him.

He leaned in and kissed her forehead. "Yeah. I want to be there with you. I know you can handle yourself, but... I got your back," he whispered.

Dean sighed. "They're making it look like it's gonna be easy, and I don't wanna scare you guys off, but this is gonna be dangerous."

Cassandra was a bit surprised that she was so taken by Derek that she had forgotten that she was in front of everyone. She looked toward everyone, her loving expression turned serious. "If you choose to come, know that I will be there ready to heal you at any given time."

"You guys should go," Stiles said with almost a saddened voice. "It'll...It'll make you all stronger."

"It would make you stronger as well." Cassandra told him. "That is, if you decide to come."

He gave her a meek smile. "I'm nothing special...I mean, I don't have any powers to fight back with."

"Whoa, hold up. Sam and I don't have any powers either. We're human," Dean said.

Stiles looked at Dean and Sam, almost as if for the first time. How had he forgotten? "Oh...right. Okay, well, then let's do this," he said with more cheer in his voice.

* * *

Cassandra set up shop at a motel. Dean and Sam went to visit the families of the deceased and gather more information. It turned out to be demons after all.

After some recon, the demons were located at an abandoned warehouse. On the way there, Stiles had many questions.

"So, demons are like your sworn enemy, right?" Stiles asked.

Cassandra tilted her head. "I never gave it much thought."

"She used to call them abominations," Sam said.

"Used to?" Stiles asked.

"Yeah. It pretty much stopped once she became buddies with Crowley," Dean said.

"We are not buddies," Cassandra said.

"Who's Crowley?" Derek asked.

"Crossroads demon turned King of Hell." Dean said.

"What? Isn't Lucifer supposed to be the demon king?" Stiles asked.

"Lucifer was asleep for a long time, and Crowley took that as a chance to overthrow him," Cassandra said.

"Wait! Lucifer was an angel in the stories. Does that mean that he-" Stiles began.

"He's my brother." Cassandra finished.

"Oh," was all Stiles could say in return.

Cassandra didn't say any more either. She didn't really know what to say. It didn't bother her that the former King of Hell and an exiled angel was her brother. It was just something she lived with, but it was hard to put into words. Maybe she should have just said what she felt. After all, there was an awkward air after that conversation.

"We're here," Sam said abruptly.

Once everyone gathered, Dean explained the plan. "We're gonna split up into three groups. Since Sam, Cassandra, and I are the more experienced hunters, one of us will be with each group. If anyone needs emergency healing, pray to Cassandra, and she'll be with you right away. We're gonna be sneaking in, so don't make more noise than you have to."

"Oh," Cassandra said. Everyone turned towards her. She disappeared and reappeared with several angel blades in hand. She gave them each one. "These will kill the demons."

Out of nowhere, a demon appeared before them. "You're too slow," he said as he grabbed Cassandra and disappeared.

Cassandra was barely able to shout Derek's name before she was completely gone.

"CASSANDRA!" Derek shouted back, reaching out for her, only to grab air.

"Shit," Dean muttered.

"Well, guess we won't be sneaking in anymore. We'll-" Sam began.

"We'll be going in guns blazing." Dean finished.

* * *

"Let me go!" Cassandra shouted, pulling away from the demon that took her. She quickly spun around with her blade in hand and stabbed him. As he flashed orange and fell to the ground, she became aware of the person behind him. Her eyes widened.

He clapped. "Cassandra! What a lovely surprise! What brings you to my humble abode?"

"Lucifer," Cassandra whispered in shock. She managed to compose herself. "Your demon is what brought me here."

"Is that so?" Lucifer questioned sarcastically.

"What is that you want?" Cassandra asked.

Lucifer rolled his eyes and huffed. "Gabriel told me about your significant other. I wanted to meet him, so I brought you all here."

"Brought us here?" Cassandra asked.

 _How could that be possible?_ Cassandra thought.

"Please, this isn't the first time I gave the Winchesters a suggestion," Lucifer said.

"If you wanted to meet Derek, you could have just asked," Cassandra said, her shoulders loosening. She put her blade away.

Lucifer gave Cassandra a look.

"Would you really have come?" He asked. Cassandra looked away from him and didn't reply. "See, now you know why I went through this whole facade."

"Are you going to hurt him?" Cassandra asked, still not meeting Lucifer's eye.

Lucifer smiled. "Well, that depends."

Cassandra glared at Lucifer.

Lucifer held his hands up and laughed. "I was only joking."

Everyone came pouring in the room in a panic.

"CASSANDRA!" Derek shouted. When he saw how calm Cassandra seemed, he stopped.

"Are you okay?" He asked anyways.

Cassandra nodded and smiled a bit. "Yes," she said softly.

"Ah, so this is the man of the hour," Lucifer said happily.

Derek was wary and glared at Lucifer. "And you are?"

Dean sighed. "Speak of the Devil."

Lucifer bowed sarcastically. "That would be me."

"Who is this guy?" Stiles whispered to Scott.

"I don't know," Scott whispered back.

Cassandra was about to speak but was interrupted.

"Cassandra! Lucifer wants to-" Gabriel shouted as he appeared with Michael in tow. "Oh," he said once he saw Lucifer already there.

Cassandra sighed. "These are my brothers, Lucifer, Michael, and Gabriel."

"Wh-What? This is Lucifer? The demon king guy we were talking about earlier?" Stiles asked.

"Is that why my ears were burning?" Lucifer asked, feigning bashfulness.

Michael sighed. "Please stop that. It's unbecoming and disgusting coming from you."

Cassandra walked over to Derek, grabbed his hand, and walked over to her brothers with him in tow. "I would like you to meet the man I love," she said.

"This?" Michael questioned, pointing at Derek.

"He's not a this. His name is Derek." Cassandra told him.

"Wow, even I didn't go there," Lucifer said. "So he's a werewolf. At least he isn't a-" he cleared his throat. "A human," he whispered.

Gabriel sighed. "Guys, he's right here."

"I don't care if he's here or not. The discussion at hand is whether or not a werewolf is good enough for Cassandra," Michael said curtly.

Cassandra cleared her throat and was about to speak, but Derek stepped up. "I'm sorry, but angels or not, you don't get to decide who is good enough for Cassandra. You can have your opinions, but in the end, she gets the final say."

Cassandra smiled. "That's right," she said. She held onto Derek's hand. "Whether you like it or not, Derek is the man I love. Everything that I've come to experience is because of him, and his friends, and of course the Winchesters. I like being able to be surrounded by all these people. It is my life, after all."

Lucifer huffed and looked at Scott and the rest of the pack. "You have an...interesting group of friends, Derek Hale."

Derek was taken aback.

"Angels know the names of most people." Michael told Derek.

Gabriel laughed. "They only know your name because I told them."

"You think they know our names?" Lydia whispered to Stiles.

Michael huffed. "Yes, we also know your names, Lydia."

Lydia smiled, a bit happy and a little fearful of that fact.

"A-All of us?" Stiles asked.

"Yeah, Stiles, we know you too, and Scott, and Malia, and Kira." Gabriel said.

Gabriel turned to Lucifer and Michael. "Well, now that you knuckleheads met Derek, let's get going. They want to spend time together. Can't you see that?"

Lucifer, Michael, and Gabriel disappeared. The room became silent, no one saying a word.

Cassandra turned around with a slight smile. "Forgive my brothers. They are not very accustomed to human interaction." She squeezed Derek's hand for reassurance. "Let's go home."

THE END


End file.
